The control of bacterial contamination is an important issue during the processing of poultry for human consumption. Cross-contamination of bacteria from one bird to another may be exacerbated by the mass processing of poultry and the use of automated production equipment. Operations such as chilling poultry carcasses in a chiller bath provide avenues for cross contamination through the use of a tank of chilled water that is reused to chill many poultry carcasses. Feather removal processing steps may also introduce bacteria onto the poultry from fecal matter originating in the poultry carcass' lower intestine. Secondary contamination sources, such as manual processing steps, may also create risks of bacteria contamination of poultry from handlers.
Current methods of removing bacteria from chickens may utilize chemical treatments to kill the bacteria. For example, the water in chiller baths used to lower the temperature of poultry during processing, may also be treated with chlorine, sodium hypochlorite or other chemical treatments known in the art to kill the bacteria. Multiple washing steps may also be used to reduce bacterial contamination during processing by washing the poultry carcasses after each processing step.
An example of control techniques for bacterial contamination, U.S. Pat. No. 6,547,659 to Adachi et al., describes the use of multiple rinsing steps during processing, and a sterilizing step where poultry carcasses are sterilized during chilling in the chilled bath. Sterilization in the chiller bath may include chlorine solutions, or other chemical solutions added to the bath to kill any bacteria present.
It is recognized that killing or preventing bacterial contamination at an early stage of processing is preferred. The current methods of decontaminating the poultry carcasses are insufficient in that they are usually dependent on water-bourne chemicals or simple washing to remove bacteria. Such washing or chemical bath methods are undesirable because the wash solution may become contaminated with bacteria when used to process multiple poultry carcasses, and thus may exacerbate the problem the methods were designed to resolve. These washing steps also occur later in the processing process, after processing has opened the bird and exposed the meat of the poultry to the bacterial contamination.
The poultry processing device and method described in this application provide for decontamination from bacteria at a very early stage in the processing, before the poultry has been killed or cut open in any way. Further, the microwaves used to decontaminate the poultry may reach all areas of the carcass without the limitations of a water-borne treatment, which may not effectively contact all areas of the carcass. The poultry processing device described herein is non-invasive and can be utilized on live poultry without causing pain or damage to the animal.
The removal of feathers from poultry is also an important part of poultry processing. Various methods for loosening the feathers prior to plucking have been developed, to provide for more complete feather removal. One known method to loosen feathers is to submerge the poultry carcass in hot water to scald the poultry carcass, thereby causing the feather follicles in the skin of the carcass to dilate or open, thus loosening the feathers in the follicles. This method has a number of disadvantages, such as poor feather removal unless scald bath temperature is uniform, discoloration of the carcass if the temperature of the scald bath is too high, and contamination of internal organs with water if the poultry is still alive. The inventive device and method disclosed herein loosens feather quills from the associated follicle by degrading the protein strand which secures the feather in the follicle. Once the quill is loosened in the follicle, feathers may be dislodged by force, such as hand or machine plucking, or with jets of compressed air.
The processing device and method described herein provide for the loosening of feathers by exposure of the chicken carcass to radio frequency electromagnetic radiation, without the problems caused by the existing methods of loosening feathers.